Safety device for elevators.



,267. PATENTED JUNE 14,-1904 U. S. ALZ. SAFETY DEVICE FOR ELEVATORS;

APPLIOATION'IILED APR. 5, 1902. 10 10mm.

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PATENTED JUNE 14, 1904.

U. S. ALZ. .SAFETY DEVICE FOR ELEVATORS.

' APPLICATION FILED APR. 5. 1902.

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UNITED STATES I-atenteq June 14, 1904;

PATENT ()EEICE.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 762,267, dated June 14, 1904.

Application filed April 5, 1902- Serial No. 101,543. (No model.)

To all whom it mwyconcern:

Be it known that I, 'URBAN S. ALZ, a citizen of the United States, and .a resident of Baltimore, in the -State of Maryland, have invented certain new and useful Improvements in Safety Devices for Elevators, of which the foll-owing is a specification.

This invention is an rovement upon the "devices set forth in my prior patent, dated July t, 1899, No. 628,260, and the patent granted to myself and August H. Hoenisch November 26, 1901, No. 687,187.

The primary object of the present invention is to provide the pneumatic cushion devices with means whereby the air-pressure in the cylinders will be relieved automatically when the car is stopped at any point, so .as to permit said car to be operated for regular trips, and whereby the relief-valve will be closed while the car is descending, and so as to arrest the downward movement of the car in case of accident.

A further object of the invention is to improve the particular construction and arrangement of the parts, so that they will be more conveniently located and the air-pipes properly protected. v

With the above objects in view the inventionconsists in the particular construction and combination of the parts, all as hereinafter fully described, and more specifically set forth in the appended claim.

In the accompanying drawings, which form a par-t of this specification, Figure 1 is a side elevation showing the application of my invention. Fig. 2 is a plan view with the top covering-plates removed. Fig. .3 is a vertical sectional view on the line 3 3 of Fig. 2. Fig. 4 is a vertical sectional yiew on the line i 4: of Fig. 2. Fig. 5 is .an end View. Fig. :6 is a detaii view of the relief-valve and the means for automatically operating the same.

Like letters of reference indicate like parts in the several views of the drawings.

A designates the-elevator-car, and-a the bottom of the same, and in carrying ou-t my present invention 1 shall prefer to locate the devices upon the said bottom a, covering-said devices with a sheet-metal plate 5, over which is placed :a top plate I), the latter forming the floor of the car and upon which may be placed a rubber mat or a carpet, as is usual.

The sides of the casing which incloses the safety devices are made up of boards ofsu i-t able thickness, while the bottom 11 is preferably sheet metal, and midway between the covering-plate b and bottom plate?) is a horizontal partition-plate Z), the ends of which are bent in opposite directions, as shown, so

that each will form an end of the spaces or compartments formed by the aforesaid plates. Located in each space or compartment are two cylinders 0, those in one compartment being located at the opposite end from those in the other compartment, and the ends of each pair of cylinders are closed by plates or yokes 0., extending from one to the other, the said yokes being clamped upon the ends of the cylinders by means of connecting-rods or long boltsc', the latter passing also through the vertical end portions of the partition-plateb seams to reinforce the yoke at that end of the cylinder, inasmuch as said end of the cylinder is to be tightly closed and for this purpose is provided witha washer 0 against which the endof the cylinder bears. The yokes c at the forward ends of the cylinders are provided with openings through which the piston-rods (6 pass, and said openings are of suflicient size to permit the free passage of air into and out of the cylinder in the rear of the piston D, it being understood that the air is compressed in the cylinder in front of said piston. The piston D is a solid piston, provided with the usual packing-rings. To the outer ends of the piston-rods of each pair of cylinders is connected at cross-bar 'E, preferably .made up of a plurality of metal plates brazed together at their ends and further connected by rivets. The ends of these cross-bars are provided with shoes e, which travel upon the inclined tracks 0, disposed at the opposite sides of theelevator-shaft .and converging, as in the aforesaid patents. The said cross-bars work between wear-plates f, having the guide-flanges f.

Hd-esignates a closed air-chamber, which is located between the upper cylinders and connected thereto by the pipes h h and to the that in case any one of the cylinders should burst the air could not enter the other cylinlower cylinders by the pipes 77 '11 the said pipes it and i beinglctinto the end boards, as'shown, and pass in to the cylinders at the upper part of the same. Adjoining the cylinders each pipe /2 and is provided with a check-valve 7M, respectively, through which air may pass to the cylinders upon an outward movement of the pistons, but which will close upon an inward movement of said pistons. These check-valves are for the purpose of permitting the cylinders to draw in air while the elevator-car is ascending and are adapted to close when the car is descending, so that the descent of the car will be checked or arrested by the air which is compressed by the moving pistons. In the prior patents hereinbefore referred to the air-pressure in the cylinders was v relieved by valves under the control of the operator, so that the car could be permitted to descend in making ordinary trips; but inasm uch as this arrangement was not altogether satisfactory and to prevent the possibility of accident in the operation of the valve I now purpose to provide a valve which is operated automatically. For this purpose Irun a pipe on from the air-chamber H to a point below the bottom of the car, where it is connected to a valve M, and to the stem of this valve is attached a wing O, the stem having a bearing in hangers 0 0, secured to the under side of the bottom of the car. The opening through the valve-plug is so arranged with respect to the valve-easing and wing that when said wing is raised the valve will be closed and when it is -lowered said valve will be open. The wing is raised by the pressure of air against the underside of the same, which takes place as the cal-descends, and when the car is stopped the wing will fall by gravity and open the valve. When the valve is open, the air-pressure in the cylinders will be relieved, the said cylinders being connected to the air-chamber. The pipes which enter the air-chamber from the cylinders are provided with check-valves a, as in the aforesaid patent, No. 687,187, so

ders.

The cylinders C are preferably made up of tubing around which is wrapped wire, the coils being brazed together, and by making the cylinders in this manner they will withstand considerable pressure.

The top of the casing is provided with angle-plates t at opposite sides, which are located over the travel of the cross-bars, so as to strengthen the device at these points and take up the strain which comes upon the easing when the car is stopped by the air cushions or cylinders. The casing is bolted to the bottom of the car by arod c at each side, which has a hooked end engaging the vertical flange of the angle-plates a.

In the regular running of the elevator-car air will be drawn into the cylinders through the check-valves 7L and z" when the said car is moving upward, and when the car descends from an upper floor to a lower one the wing 0 will be raised by the pressure of air under the car, and, closing the valve M, the air will be compressed in the cylinders and air-chamber. As soon as the car is stopped at any floor the wing drops, and, opening the valve M, the pressure in the air chamber and cylinders will be relieved, so that the car maymake another descent. In case of an accident and the car should drop the pressure in the cylinders would stop the car, and the wing falling would open the valve M, allowing the air to escape to the extent only of permitting the car to again move, when the valve would again close and the car stop, and so on until it reached the bottom. It will therefore be noted that in case the car should fall at a considerable height in a building it would descend a short distance and stop, descend again and stop, and so on to the bottom of the shaft, it being understood that each stop of the car in its descent would be gradual, owing to the fact that the air is gradually compressed in the cylinders. It will also be understood that it is impossible to run the car from the top of the shaft to the bottom faster than a moderate speed without a stop, inasmuch as the automatic device for regulating the relief-valve is without the control of the operator. This provides a safeguard against a toorapid running of the car. As the cylinders would not operate to the desired extent in case the car should drop from a cornparatively short distance from the bottom of the shaft, I purpose to provide auxiliary cushions comprising vertical tubes w, located in the corners of the shaft and having rods 20 with pistons working in said tubes, the rods being adapted to engage the top of the car at the corners thereof. Said rods are provided with washers or stops it, engaging the upper ends of the tubes. The corners of the car are cut away, as shown, to permit the passage of the rods. The upper part of each tube is cut away at opposite sides, as shown, and within said open portion of the tube is mounted on the rod in a helical spring e0 adapted to lift the rods to their normal position. The pistons on the lower ends of the rods are the ordinary leather-disk pistons.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In a safety device for elevators, the combination, of the closed cylinders having pistons therein, cross-bars connected to said pistons and sliding upon inclined guide-bars, an airchamber, a' pipe m connected at one end to said air-chamber, a valve M at the other end of said pipe, and a wing 0 connected to said cylinders independent of thevalve M,as herein valve and operating automatically to open shown and for the purpose set forth. 1 and close the same; together with pipes h con- In testimony whereof I affix my signature in necting each cylinder independently to the the presence of two witnesses.

air chamber, and a check-valve h in each URBAN S. ALZ.

pipe and located between the air chamber and l/Vitnesses:

cylinders, said check-valves having air-inlets HENRY C. l/VEAVER,

whereby to admit air to the air chamber and J. ALEX. HILLEARY, Jr. 

